Gasket sealing material for fuel cells

Abstract

A gasket sealing material for a fuel cell comprising: at least 25% dry w/w chemically exfoliated vermiculite; and at least 15% dry w/w plate-like filler; wherein the plate-like filler has an average particle size of less than or equal to 10 μm. Gaskets, fuel cells, uses of the gasket and sealing material are also defined.

The invention claimed is: 
     
       1. A gasket sealing material for a fuel cell comprising:
 at least 25% dry w/w chemically exfoliated vermiculite; and 
 at least 15% dry w/w plate-like filler; 
 wherein the chemically exfoliated vermiculite and the plate-like filler are intimately mixed, 
 wherein the plate-like filler has an average particle size of less than or equal to 10 μm, and 
 wherein the gasket sealing material has a density prior to use of less than or equal to 1.1 g/cm 3 . 
 
     
     
       2. The gasket sealing material according to  claim 1 , wherein the plate-like filler is talc. 
     
     
       3. The gasket sealing material according to  claim 1 , wherein the plate-like filler is present at at least 25% dry w/w gasket sealing material. 
     
     
       4. The gasket sealing material according to  claim 1 , wherein the chemically exfoliated vermiculite is present at at least 30% dry w/w gasket sealing material. 
     
     
       5. The gasket sealing material according to  claim 1 , wherein more than 25% dry w/w of the plate-like filler in the gasket sealing material has an average particle size of greater than 2 μm. 
     
     
       6. The gasket sealing material according to  claim 1 , wherein the plate-like filler has an average particle size of from 2 to 10 μm. 
     
     
       7. The gasket sealing material according to  claim 1 , comprising a combination of chemically exfoliated vermiculite and plate-like filler in excess of 95% dry w/w. 
     
     
       8. A gasket for sealing two mating surfaces of a fuel cell comprising at least one sealing layer comprising the gasket sealing material according to  claim 1  and at least one of a core layer, a support layer, or a coating layer. 
     
     
       9. A fuel cell or fuel cell component comprising one or more gaskets according to  claim 8 , wherein each of the one or more gaskets is located between two mating surfaces of the fuel cell or fuel cell component. 
     
     
       10. A fuel cell or fuel cell component comprising the gasket sealing material according to  claim 1 , wherein the gasket sealing material is located between two mating surfaces of the fuel cell or fuel cell component.